This invention relates to a method of kerning that is applicable to the processing of documents in European languages so as to attain a balance between characters such as alphabetic letters, numerals and symbols.
When processing documents written in English and other European languages, the balance between typeset characters such as alphabetic letters, numerals and symbols must be considered and to this end, the space between specific character pairs is tightened up for adjustment of proportional spacing. This technique is commonly called "kerning", a typical application of which is where irregularly shaped characters such as "V" and "A" are involved; if they are typeset using normal spacing, they will appear to be too far apart and to enhance character fit, kerning is performed to have the "A" partly invade the letter region of "V".
Various kerning techniques are known in the computerized processing of documents in European languages; according to one method, the space between two characters is calculated at desired points (e.g., top, middle and bottom) and the sum or average of the calculated values is used as an index for determining the set width of each character; in another method, kerning information is preset in a character data memory. The function of the kerning information is backspacing by small amounts through several stages; a preset amount of cursor movement to the left is read out by a document processing means in accordance with the combination of specific letters in a character string and an appropriate kerning process is performed.
The kerning techniques just described above require that an appropriate set space be computed for each character or that the kerning information be read out in accordance with a specific combination of characters so as to achieve space setting. Thus, either method involves cumbersome processing while demanding a large burden on the processing equipment.